If the recommended charge cycle is 80%/20%, why isn't there a built in notification or function to do it on its own?

There is only a low battery warning at TEN PERCENT and you can't change it. And why not have a setting for a charge limit like my Tesla?

0 E922 15 days ago

Agreed 100%!

Maybe there's an app you can add to the watch to do this?

Right now, I just use a countdown timer to remind me to check the battery % every 10 minutes after plugging it in. Inexact, but works.